The invention relates to a keg-tapping assembly, for adapting a keg for the safe pressurized dispensing of beverage contents.
Kegs for delivery of beer or other beverage to taverns and restaurants are typically equipped with a so-called Barnes neck to which a draft tube is fitted, with a normally closed check valve at the upper end of the tube. The bartender is presented with the cylindrically annular configuration of the thus-fitted neck, the same being characterized by diametrically opposed inward lugs which have removable bayonet-locking engagement with a standardized base-flange configuration of slot formations, via which a keg-tapping assembly is removably assembled, with axially downward and clockwise rotary displacement in the course of establishing the bayonet connection of the keg-tapping assembly to the keg neck.
Such a keg-tapping assembly has a body with provision for receiving a supply of gas for pressurized delivery of dispensed beverage. Within the body a tubular valve member is guided for vertical displaceability; it can be actuated via down-up crank displacement of an external handle. When bayonet-fitted in tapping relation with a keg, a down displacement of the handle drives the draft-tube check valve to open position and admits pressurized discharge of dispensed beverage. In a customary tavern arrangement, the key-tapping assembly is hose-connected to a spigot which is convenient to the bartender, who controls all dispensing from the spigot.
A safety problem arises if the bartender tries to remove his keg-tapping assembly from an exhausted keg to a loaded new keg. If he has failed to raise the handle in order to vent pressure in the exhausted keg (and in order to shut off delivery of pressurized gas), there may be sufficient pressure in the keg to blast the assembly out of his hand, with resulting personal injury and property damage, not to mention unwanted discharge of some small unconsumed volume of beverage which remained in the keg.
U.S. Pat. No. 4,291,821 recognizes such a problem and seeks to solve it by providing a downward abutment which is rigid with the handle and which is intended to provide an interlock function, foreclosing handle actuation of the draft-tube check valve if the bayonet engagement is not complete. This patented device is also intended to foreclose disengagement of the bayonet lock if the handle has not been raised.
In spite of the improvement realized through said U.S. Pat. No. 4,291,821, it is found that the downward abutment of the handle can painfully foul the bartender's fingers, and there is still no clear differentiation between gas and/or beverage discharge and the bayonet-locked and unlocked condition.